Storage of a document using multiple representations

Abstract

Some embodiments provide a method for storing a document. The method stores a content stream representation of the document that includes an ordered stream of code representations for primitive elements of the document. Each code representation of a primitive element has an index that indicates the order in the content stream of the primitive element representation. The method stores an object representation of the document that includes a set of object nodes arranged in a tree structure. Each object node references a range of indices in the content stream.

Description

CLAIM OF BENEFIT TO PRIOR APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application 61 / 433,951, entitled “Reconstruction of Lists, Ordering Page Content, Storing Multiple Representations for a Document, and Adaptive Graphic Objects”, filed Jan. 18, 2011, and U.S. Provisional Application 61 / 433,963, entitled “Storage of a Document Using Multiple Representations”, filed Jan. 18, 2011. U.S. Provisional Applications 61 / 433,951 and 61 / 433,963 are incorporated herein by reference.BACKGROUND[0002]Electronic document file formats and in-memory representations used by software that process the documents will generally be either stream representations or object representations. Stream representations generally consist of a sequence of character codes or other primitive data elements into which are interspersed special non-character values or sequences of values that signal a change in state or context (e.g., text style, transform or drawing properties, or the begin...

AI Technical Summary

Benefits of technology

[0010]This multi-representation approach enables efficiency for various common document actions. Selection of a structure (e.g., a word, line, paragraph, etc.) can be efficiently performed by navigating the structure tree to find the desired structure and then using the indices to identify the content to select in the stream. Other examples of efficiently performed actions include certain navigation operations (e.g., finding a search term in a chapter heading) and conversion of a document from one format to another (e.g., in order to switch between applications).

Problems solved by technology

While each of the formats is efficient for certain operations, each format is also inefficient for other operations.

For instance, while a stream representation is useful for string searches and other processing that does not depend on detailed knowledge of object properties, the stream representation will not be useful for accessing a particular object.

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